Guns For Beginners: How to Zero Your Rifle in One Shot (Or Almost)

There are few things more frustrating than wasting ammo trying to get your rifle zeroed. If you just can’t find the paper or can’t seem to chase that zero down, turning expensive ammunition into nothing but noise gets old real fast. Since I’m constantly bolting optics onto loaner rifles, I thought I’d share how I get zeroed at 100 yards with as few rounds fired as possible.

Jeremy S. for TTAG

First and foremost — non-negotiable to this process, actually — is a rock-solid rifle rest. Jon Wayne Taylor and I have gravitated to the Caldwell Stinger this year, but there are many Lead Sled options and other inexpensive ones that use straps and clamps to keep things stable.

Keep in mind you don’t actually have to shoot from this rest. You do need to shoot in as accurate a manner as you and your rifle are capable of, but the rest is only needed for holding the rifle absolutely steady while you’re making adjustments to your optic.

Jeremy S. for TTAG

Bore Sighting

Your first step is to establish a rough zero. The only goal of this step is to land your first bullet anywhere at all on the target.

If you’re shooting a bolt action rifle, remove the bolt. If you’re shooting an AR platform rifle, remove the upper receiver, then remove the bolt carrier. With the rifle or upper (or whatever assembly contains the barrel and mounted optic) on the rest or otherwise held absolutely as rock steady as physically possible, look right down through the barrel.

Jeremy S. for TTAG

The chamber end will be a larger circle and the muzzle end a smaller one. To ensure you’re looking straight down the centerline of the bore, center that muzzle circle in the chamber circle.

Adjust your rifle rest set up until you have the target — visible through the barrel — centered in the bore. It’s more difficult to be precise with this if you have a short barrel with a large bore rather than a long barrel with a small bore, though seeing the target while using the barrel as a zero-magnification telescope is easier. Try to get your eye closer to the chamber if you’re having difficulty seeing your target through the barrel.

Once your barrel is on target, it’s time to get your rifle scope on target. DO NOT MOVE the rifle AT ALL during this process, or it won’t work.

Run the turrets until the reticle is centered on the bullseye. Usually that’s clockwise on the elevation turret to move the reticle up and clockwise on the windage turret to move the reticle right, but knowing which is which doesn’t much matter. Just turn ’em and watch the reticle move and move it to the center of the target.

Confirm that the target is still in the center of the bore when you look through the barrel.

You’re now bore sighted. This is a [very] rough zero. You can also use a laser bore sighter to accomplish this, but they’re often very difficult to spot at 100 yards in daylight. If it’s visible, though, it’s even easier than looking down the bore.

Jeremy S. for TTAG

Firing and Adjusting

Get stable — remember those fundamentals — and fire a shot. If you know your rifle and ammo combination is extremely accurate and feel confident you made a good shot, one round can suffice. If it’s a new gun or a gun that puts up a bit of a spread, fire three to five shots to create a group. You’ll use the center of this group for the next step.

Re-adjust the rest (or put the rifle back on it if you weren’t shooting from it) so the reticle is, once again, perfectly centered in the bullseye.

Jeremy S. for TTAG

Now, dial the turrets until the crosshair is on your bullet hole (or centered in your shot group).

You’re zeroed!

At least, in theory. You’ve matched up your rifle scope’s point of aim with your rifle’s point of impact, and that’s what this game is all about. It may be nice to confirm things with another shot(s), though, and do any fine-tuning that’s needed.

You may also want to consider tapping your turrets with a little tool or a round of ammo or something. Not enough to move the rifle at all, of course, but enough to unstick the widgets inside the scope just in case your hardware is old, cheap, etc. Then make sure it’s still centered on that bullet hole.

Jeremy S. for TTAG

Bingo! I got quite lucky when I chose to go through this process on camera for the video above — the confirmation shot was effectively dead-on with this ~1 MOA rifle (which I’d normally give the 5-shot group treatment). “In real life” I expect to do a final fine-tuning if I want the rifle and ammo combo to be truly dead-on zeroed.

There you have it: a straightforward zeroing process for jumping right to 100 yards, sighting in, getting your first shot on paper, and zeroing your scope quickly. And all while using as few as one single round of ammo.

comments

Since I seem to be constantly swapping optics between AR platforms, I have found one of those laser cartridge bore sighters very handy too. Since the author is dealing with many different calibers, his is the much more economical method.

A friend of mine swapped out his old scope for a new one right before a hunting trip. He was in a hurry so tried the one shot zero method. 20 rounds later he left the range in frustration. He showed me the rifle and you could hear the forehead slap around the world. He mounted his scope 90 degrees counter clockwise.

He could get the zero close but the final few clicks would make no sense.

My success with the laser sight tool has been poor. I had my lgs set a couple scopes with his laser rig, the result was not even on paper. I have tried with my own inexpensive laser bore sighter with similar results. But when I have used the manual method it has worked well. My .02 and observations are worth what you paid, no more.

Only one problem with Zeroing In a Rifle Barrel! “Ambient Temperature and Barrel Temperature” which effect the Aim. It’s easy to Zero a Scope, which is simply Line Of Sight and isn’t effected by Ambient Temperature…

It’s good advice. I’ve used both the eyeball down the bore method and the laser “cartridge” types. Both work with care and attention to detail.

Some of the laser gadgets are adjustable with tiny screws. You set it in a V-block, could just be two pieces of 2×4 clamped together. Rotate the laser in the V-Block and see how much of a circle it makes on a wall or a target. If it’s really off, start close. Adjust the screw to make the circle smaller. Increase the distance and check again.

A “Laser Cartridge” is most effective with a “Bolt Action” where cyclic rate is very low. Not so great where cyclic rate is high, which will Heat Up a Barrel Extremely Fast cause the barrel to Drupe with every round fired…

My idiot buddy put his bore sight cartridge in the mag and charged his AR to get it in the chamber. Of course that little aluminum body didn’t like the full impact of the bolt slamming home and the extractor ripped it apart when he tried to eject. The real dumbass that day was me, as I lent him my pocket tool to try and get the remains out of the chamber and of course he broke that as well.

Pro-tip: know what the wind is doing to your bullet at your range or else your zeroing process will be inaccurate.

Consider a rifle chambered in .243 Winchester loaded with 100 grain bullets that exit the muzzle at 2950 fps and have a ballistic coefficient of 0.381. A simple 10 m.p.h. cross wind would cause your bullet to hit 1.2 inches to the left/right (depending on which the wind is blowing) of your point of aim!

Unless you are shooting in calm conditions, this is something to seriously consider if you want your rifle to be accurate beyond 200 yards. Personally, I now sight-in at 50 yards which reduces wind effects: in that same example above, the cross wind would only push your bullet over 0.4 inches.

I also recently discovered that temperature can effect your rifle’s zero.

I have a break-action .44 Magnum rifle that I use for deer hunting. I chronographed it using the same box of ammunition when it was 70 degrees outside and when it was 35 degrees outside. When the rifle and ammunition was 70 degrees, bullets exited the muzzle at 1,900 fps. When the rifle and ammunition was 35 degrees, bullets exited the muzzle at 1,700 fps. That difference of 200 fps changes the trajectory of the bullet and hence the point of impact.

The fun question: what factor or factors caused the slower muzzle velocity at cold temperatures? Is that particular smokeless powder less energetic when it is cold? Did the barrel diameter shrink 0.0005 inches, which caused more friction on the bullet and lower muzzle velocity? Does the cold barrel absorb so much heat from the expanding gases that it reduces gas pressure in the barrel and hence muzzle velocity?

Powders (some) are known for being very sensitive to temperature. More of a concern in certain types of rifle shooting, the powder manufactures have made powders to resist the effects temperature, such as Hodgdon Extreme line of powders.
I can not recall the same effort for pistol powder temperature stability.

Forgive my ignorance because I just got my first AR (actually my first rifle) not too long ago but on my AR my scope is on my lower but the article says I need to put the upper with the optic attached into the rest to bore sight the target. Once I do that and have to put the scope back on the lower won’t everything be out of whack? Or is it going to be close enough I just need to make small adjustments?

Lol you’re right thanks for clearing that up for my feeble mind. I was thinking of the actual barrel and hand guard part and not the upper it’s attached to. If I would have just looked at it I would have seen that. Now I can actually zero it. I should have known better since I’m the one who assembled it in the first place. Although showing how dumb I am with that question I did actually manage to put all the parts together right and despite not being zeroed it was fairly accurate out to 25 yards with 200 rounds so far with no issues.

If you installed the barrel on your upper (as opposed to buying a complete upper) it is a good idea to have the headspace checked. Even if you bought a complete upper, if you have access to a gunsmith and extra cash it would be safer to have the headspace checked. I had a factory upper that was headspaced incorrectly. They replaced the upper since it is difficult to repair economically. With a factory upper this is a rare occurrence but it does happen occasionally.

The plain old fashioned bore sighter, no electronics please, works quite well too, though the bore sighting process described will usually work out well, especially with bolt action rifles. In the past, when I bore sighted a rifle, I would fire 3 shots, to get a group, and adjust from that data base. Worked out quite well.

I started using this method back in 1980 to save ammo and getting a quick zero.
It raised some eyebrows but it worked for me. It is nothing new. I saved a lot of
ammo but I first use a boresighter to be on paper for the first shot at 100 yards.
i never sight a rifle at 25 yards, it is optional but not necessary.